zephyr/drivers/gnss/gnss_nmea0183_match.h

/*
 * Copyright (c) 2023 Trackunit Corporation
 *
 * SPDX-License-Identifier: Apache-2.0
 */

/*
 * The GNSS NMEA0183 match is a set of modem_chat match handlers and a context to be
 * passed to said handlers, to parse the NMEA0183 messages received from a NMEA0183
 * based GNSS device.
 *
 * The context struct gnss_nmea0183_match_data *data is placed as the first member
 * of the data structure which is passed to the modem_chat instance through the
 * user_data member.
 *
 *   struct my_gnss_nmea0183_driver {
 *           gnss_nmea0183_match_data match_data;
 *           ...
 *   };
 *
 * The struct gnss_nmea0183_match_data context must be initialized using
 * gnss_nmea0183_match_init().
 *
 * When initializing the modem_chat instance, the three match callbacks must be added
 * as part of the unsolicited matches.
 *
 *   MODEM_CHAT_MATCHES_DEFINE(unsol_matches,
 *           MODEM_CHAT_MATCH_WILDCARD("$??GGA,", ",*", gnss_nmea0183_match_gga_callback),
 *           MODEM_CHAT_MATCH_WILDCARD("$??RMC,", ",*", gnss_nmea0183_match_rmc_callback),
 *   #if CONFIG_GNSS_SATELLITES
 *           MODEM_CHAT_MATCH_WILDCARD("$??GSV,", ",*", gnss_nmea0183_match_gsv_callback),
 *   #endif
 *
 */

#ifndef ZEPHYR_DRIVERS_GNSS_GNSS_NMEA0183_MATCH_H_
#define ZEPHYR_DRIVERS_GNSS_GNSS_NMEA0183_MATCH_H_

#include <zephyr/types.h>
#include <zephyr/device.h>
#include <zephyr/drivers/gnss.h>
#include <zephyr/modem/chat.h>

struct gnss_nmea0183_match_data {
	const struct device *gnss;
	struct gnss_data data;
#if CONFIG_GNSS_SATELLITES
	struct gnss_satellite *satellites;
	uint16_t satellites_size;
	uint16_t satellites_length;
#endif
	uint32_t gga_utc;
	uint32_t rmc_utc;
	uint8_t gsv_message_number;
};

/** GNSS NMEA0183 match configuration structure */
struct gnss_nmea0183_match_config {
	/** The GNSS device from which the data is published */
	const struct device *gnss;
#if CONFIG_GNSS_SATELLITES
	/** Buffer for parsed satellites */
	struct gnss_satellite *satellites;
	/** Number of elements in buffer for parsed satellites */
	uint16_t satellites_size;
#endif
};

/**
 * @brief Match callback for the NMEA GGA NMEA0183 message
 *
 * @details Should be used as the callback of a modem_chat match which matches "$??GGA,"
 */
void gnss_nmea0183_match_gga_callback(struct modem_chat *chat, char **argv, uint16_t argc,
				      void *user_data);

/**
 * @brief Match callback for the NMEA RMC NMEA0183 message
 *
 * @details Should be used as the callback of a modem_chat match which matches "$??RMC,"
 */
void gnss_nmea0183_match_rmc_callback(struct modem_chat *chat, char **argv, uint16_t argc,
				      void *user_data);

/**
 * @brief Match callback for the NMEA GSV NMEA0183 message
 *
 * @details Should be used as the callback of a modem_chat match which matches "$??GSV,"
 */
void gnss_nmea0183_match_gsv_callback(struct modem_chat *chat, char **argv, uint16_t argc,
				      void *user_data);

/**
 * @brief Initialize a GNSS NMEA0183 match instance
 *
 * @param data GNSS NMEA0183 match instance to initialize
 * @param config Configuration to apply to GNSS NMEA0183 match instance
 */
int gnss_nmea0183_match_init(struct gnss_nmea0183_match_data *data,
			     const struct gnss_nmea0183_match_config *config);

#endif /* ZEPHYR_DRIVERS_GNSS_GNSS_NMEA0183_MATCH_H_ */